An organic light-emitting diode (OLED) display device is a device that utilizes a reversible discoloration phenomenon generated by driving an organic semiconductor material under a current to realize a graphical display. The OLED display has advantages of ultra-light, ultra-thin, high brightness, large viewing angle, low voltage, low power consumption, fast response, high definition, shockproof, flexible, low cost, simple process, raw used materials, high luminous efficiency and wide temperature range and so on; therefore, an OLED display technology is considered as the most promising new generation of a display technology.
A basic structure of the OLED display device comprises: an anode layer, a cathode layer, and an organic light-emitting layer between the anode layer and the cathode layer. Generally, the organic light-emitting layer is deposited on the anode layer through an evaporation process. However, at the time of performing the evaporation, because an upper limit of an angle of an evaporation source is present, an evaporated organic light-emitting layer tends to be uneven. Specifically, as shown in FIG. 1, the anode layer 4′ is connected to a drain electrode 2′ covered by a flat layer 3′ through the flat layer 3′. A thickness of a material at both end areas of the organic light-emitting layer 6′ on the anode layer 4′ (that is, at the b′ area shown in FIG. 1) is thinner than the thickness of the material of a central region (that is, at the a′ area shown in FIG. 1), which the flat layer 3′ is below the anode layer 4′. As a result, when the OLED emits light, it is prone to present the situations that a light-emitting unit around emits the light unsaturated and a brightness is lower than the light-emitting unit of the central region as shown in FIG. 2, resulting in an OLED light color mixing, and affecting an effect of the display.